Name two processes that are important in the carbon cycle. Options: a. Photosynthesis and nitrification b. Nitrification and respiration
c. Photosynthesis and respiration d. Nitrification and denitrification

I'm thinking it's A but am unsure.

Which medullary index indicates a human hair? a. 0.653 b. 0.733 c. 0.516 d. 0.256

Why does meiosis produce cells with half the chromosomes? o a. most of the chromosomes are not necessary to keep an organism alive. b. a gamete needs only half the number of chromosomes because two gametes join together. o c. it makes the gametes easier to move around in the organism. o d. it is faster to produce gametes with fewer chromosomes.

Some birds look for food near cattle and other livestock. the movement of the cattle churns up the ground, making insects available to the birds. the cattle appear to be unaffected by the presence of the birds. what kind of relationship exists between the birds and the cattle? o a. parasitism o b. commensalism o c. predation o d. mutualism